All questions of Photosynthesis for UPSC CSE Exam

Explanation:
Dark Reaction in Photosynthesis:
Photosynthesis is a process that occurs in plants where they use sunlight to convert carbon dioxide and water into glucose and oxygen. It consists of two main stages - the light reaction and the dark reaction. The dark reaction, also known as the Calvin Cycle, is called so because it does not directly require light energy to function.
Light-Independent Reaction:
The dark reaction is also referred to as the light-independent reaction because it does not depend on the presence of light to proceed. While the light reaction requires sunlight to produce ATP and NADPH, which are used in the dark reaction, the dark reaction can occur in the absence of light.
Occurrence:
Contrary to its name, the dark reaction can occur during the day as well as night. However, since it does not rely on light energy, it can continue in the absence of sunlight, which is why it is sometimes more active at night.
Calvin Cycle:
The dark reaction takes place in the stroma of chloroplasts and involves a series of biochemical reactions known as the Calvin Cycle. During this cycle, carbon dioxide is fixed into organic molecules, ultimately producing glucose. This process is essential for the plant's growth and development.
Conclusion:
In conclusion, the dark reaction in photosynthesis is named so because it does not directly require light energy to function. It can occur during both day and night, making it a crucial part of the overall process of converting sunlight into energy for plants.